1. Field of the Invention
The present invention relates to spoken dialog systems and more specifically to a method of building a spoken language understanding module within a spoken dialog system.
2. Introduction
Spoken dialog systems typically include a variety of core modules that receive and process data to understand speech from a user and prepare an appropriate response. These modules include an automatic speech recognition module, a spoken language understanding module, a dialog management module and a text-to-speech module. To generate the speech models in order to create an effective spoken dialog system for a particular application, such as the AT&T VoiceToneSM service that assists users with telephone billing and account questions, requires a large amount of specialized work by developers to create the various modules that will work in the application's context. The present invention will relate to the spoken language understanding portion of a spoken dialog system. There is much information available related to the basic process of generating spoken dialog systems. Accordingly, no further information is provided herein other than this introduction.
There is no single way of building a spoken language model for a spoken dialog system. Typically, the same data, tools and labeling guide may be used by different developers but can result in completely different models with varying performance capabilities. Furthermore, given the variety of contexts in which spoken dialog systems may be developed, there may be differences in models with difference performance characteristics based on the context of the spoken dialog systems. For example, various development projects depending on the context (airline reservation service, bank account management service, auction service, etc.) can vary in the process by which a developer may create the spoken language understanding portion of the spoken dialog system. What is needed in the art is a process that is uniform over most development projects and that can further lead to reproducible results.